Findbugs fixes

Testing Sonar with a few findbugs fixes.  Suppressing a false
positive to see if it works.

Change-Id: I0cdf2921198787adc56c680840aa00bdd254269b
diff --git a/core/store/dist/src/main/java/org/onlab/onos/store/service/impl/ClusterMessagingProtocolClient.java b/core/store/dist/src/main/java/org/onlab/onos/store/service/impl/ClusterMessagingProtocolClient.java
index 3dd93b9..f8c1be8 100644
--- a/core/store/dist/src/main/java/org/onlab/onos/store/service/impl/ClusterMessagingProtocolClient.java
+++ b/core/store/dist/src/main/java/org/onlab/onos/store/service/impl/ClusterMessagingProtocolClient.java
@@ -94,6 +94,9 @@
     }
 
     @Override
+//    @edu.umd.cs.findbugs.annotations.SuppressWarnings
+//            (value="NP_NONNULL_PARAM_VIOLATION",
+//             justification="False positives on completedFuture call, passing null as a parameter is allowed")
     public synchronized CompletableFuture<Void> connect() {
         if (remoteNode != null) {
             // done